Dense Phase Mode of Conveying :
Dense phase conveying on the other hand is a totally different concept and is non-suspension flow. The material is filled inside a pressure vessel, which is then pressurized with the air or gas to be used for conveying. Once a pre-set pressure is reached inside the vessel, the bottom discharge valve connected to the conveying pipe of the system automatically opens and the material is “pushed” to the destination. Higher material to air loadings are possible in dense phase conveying but not all materials can be conveyed in this method. The method uses compressed air and not low-pressure air and requires an air compressor, air receiver and air dryer (Where the materials are hygroscopic). Dense phase conveying is generally used for high tonnage and long distance conveying with the assistance of air boosters (Above 10 TPH and more than 100m)
Dilute Phase Mode of Conveying :
Dense phase conveying on the other hand is a totally different concept and is non-suspension flow. The material is filled inside a pressure vessel, which is then pressurized with the air or gas to be used for conveying. Once a pre-set pressure is reached inside the vessel, the bottom discharge valve connected to the conveying pipe of the system automatically opens and the material is “pushed” to the destination. Higher material to air loadings are possible in dense phase conveying but not all materials can be conveyed in this method. The method uses compressed air and not low-pressure air and requires an air compressor, air receiver and air dryer (Where the materials are hygroscopic). Dense phase conveying is generally used for high tonnage and long distance conveying with the assistance of air boosters (Above 10 TPH and more than 100m)
Dilute phase is essentially suspension flow wherein the material to be conveyed is introduced into a moving air stream inside a pipeline. For the material to remain in suspension there is a minimum conveying velocity which varies for different materials. The quantity of material that is fed into an air stream is also dependent on material characteristics like bulk density, particle size, sieve analysis, frequency distribution etc. Generally, the upper limit for material loading is approx. 6 to 10 kg. of material per kg. of air. Conveying velocities are in the region of 20 to 30m/sec. depending on the product.
The dilute phase conveying system uses low-pressure air at pressures less than one bar, which is generated by positive displacement blowers or by centrifugal fans
